1. Field of the Invention
This invention relates to an indium source reagent composition having utility for incorporation of indium in a microelectronic device structure, e.g., as an indium-containing film on a device substrate by bubbler or liquid delivery MOCVD techniques, or as a dopant species incorporated in a device substrate by ion implantation techniques. The invention also relates to such semiconductor fabrication techniques for using the indium source reagent of the invention, as well as to microelectronic device structures incorporating indium by use of such source reagent and techniques.
2. Description of the Related Art
In the field of semiconductor manufacturing, indium is a material of considerable current and future technological importance.
With the emergence and proliferation of copper as a preferred material in metallization for formation of conductor transmission lines of integrated circuitry devices, copper-indium (Cu/In) alloys are of great interest for improving the long-term performance, electro-migration resistance and reliability of copper-based interconnects. Indium-containing III-V semiconductor materials also will play an increasingly important role in the development of electronic and optoelectronic devices.
The most commonly used In precursors for the deposition of In-based materials are trialkylindium, such as trimethylindium and triethylindium. For the chemical vapor deposition (CVD) of Cu/In alloys, such conventional In precursors are not compatible with currently used Cu precursors, when multiple source precursors (for In and Cu) are introduced. In addition, the conventional In precursors are extremely sensitive to air, oxygen and moisture, leading to vigorous exothermic reactions, fire and explosions when exposed to such ambient atmospheric constituents.
Indium also is of great current interest in the microelectronics field as a potential dopant species for the formation of doped shallow junctions in integrated circuitry devices, since shallow device junctions enable high performance devices to be fabricated at lower switching voltages than are required for junctions of greater depth. Further, in relation to other dopant species that may be employed for forming doped junction structures by conventional ion implantation techniques, indium has the significant advantage that its size and mass allow lower implant energies to be used, provided that useful beam currents of In ions can be obtained.
The beam current is a critical aspect of the ion implantation operation as practiced in conventional ion implanter systems, and is strongly precursor material-dependent in character. Specifically, the vaporization and delivery of the precursor for ionization and ion beam transport of the implant species typically requires a material of suitable volatility and transport characteristics, but volatile liquids and solids when used as precursors also create a potential risk of introduction of reactive species that are susceptible to side-reactions and also create the potential for contamination of the substrate and disruption of the desired device characteristics.
Given these circumstances, there is a compelling need in the art for new In precursors suitable for deposition of In-based materials or ion implantation of In in semiconductor device structures.
This invention relates in one aspect to an indium source reagent composition useful for incorporating indium in a microelectronic device structure, e.g., as an indium-containing film on a device substrate by bubbler or liquid delivery MOCVD techniques, or as a dopant species incorporated in a device substrate by ion implantation techniques.
The invention also relates to such semiconductor fabrication techniques for using the indium source reagent of the invention, as well as to microelectronic device structures incorporating indium by use of such source reagent and techniques.
In one aspect, the invention relates to an indium precursor composition of the formula:
R1R2InL 
wherein:
R1 and R2 may be same or different and are independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, or C1-C6 fluoroalkyl C1-C6 perfluoroalkyl; and
L is xcex2-diketonato or carboxylate.
Another aspect of the invention relates to an indium precursor composition of the formula: 
wherein:
Rxe2x80x2 and Rxe2x80x3 may be the same or different and are independently selected from H, C6-C10 aryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl, and C1-C6 perfluoroalkyl; and
R1 and R2 may be same or different and are independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl, or C1-C6 perfluoroalkyl.
Still another aspect of the invention relates to a method of making a dialkyl(xcex2-diketonate)indium(III) compound, by the reaction: 
wherein:
each R may be same or different and is independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl or C1-C6 perfluoroalkyl and;
M is selected from Li, Na, or K and;
X is selected from F, Cl, Br or I.
In a further aspect, the invention relates to a liquid delivery metal-organic chemical vapor deposition process for forming a In-containing film on a substrate, comprising:
providing a liquid precursor composition including an indium precursor of the formula:
R1R2InL 
wherein:
R1 and R2 may be same or different and are independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl or C1-C6 perfluoroalkyl; and
L is xcex2-diketonato or carboxylate;
flash vaporizing the precursor to form a precursor vapor;
transporting the precursor vapor to a chemical vapor deposition reactor containing a substrate element;
contacting the precursor vapor with the substrate element in the chemical vapor deposition reactor under chemical vapor deposition conditions, to form an In-containing film on the substrate element.
A further aspect of the invention relates to a method of ion implantation of In+ ions in a substrate, comprising ionizing an indium precursor composition to produce an ionization product including In+ ions, separating In+ ions from the ionization product, and directing the separated In+ ions under ion implantation conditions into the substrate, wherein the indium precursor composition comprises an indium precursor of the formula:
R1R2InL 
wherein:
R1 and R2 may be same or different and are independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl or C1-C6 perfluoroalkyl; and
L is xcex2-diketonato or carboxylate.
Still another aspect of the invention relates to a microelectronic device structure comprising a shallow junction region containing IN+ ions derived from ionization of an indium precursor composition comprising an indium precursor of the formula:
R1R2InL 
wherein:
R1 and R2 may be same or different and are independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl or C1-C6 perfluoroalkyl; and
L is xcex2-diketonato or carboxylate.
The invention further relates to a microelectronic device structure including conductor transmission lines comprising an indium-copper composition formed by chemical vapor deposition of indium and copper from precursor material therefor, wherein said precursor material comprises an indium precursor of the formula:
R1R2InL 
wherein:
R1 and R2 may be same or different and are independently selected from C6-C10 aryl, C6-C10 fluoroaryl, C6-C10 perfluoroaryl, C1-C6 alkyl, C1-C6 fluoroalkyl or C1-C6 perfluoroalkyl; and
L is xcex2-diketonato or carboxylate.
Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.